
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.text.DecimalFormat;

public class TelTime {
	public static String bill(String sdt1,String sdt2) {

		Telephone tl = new Telephone(sdt1, sdt2);
        DecimalFormat df = new  DecimalFormat("######0.00");
        long minute =  tl.getTelephone();
        double telfee;
        if(minute == 0) {
        	return "时间错误！";
        }
        if(minute <= 20) {
			telfee = 0.05*minute;
		} else {
			telfee = 1.00 + (minute - 20) * 0.1;
		}
		return df.format(telfee);
	}
			
	
}
